http://finzi.psych.upenn.edu/R/library/fCalendar/html/3D-TimeDateSpecDates.html
try this also RSiteSearch("last day of the month") to get more pointers - Regards, \\\|||||/// \\ - - // ( o o ) oOOo-(_)-oOOo-------- | | Gaurav Yadav | Assistant Manager, CCIL, Mumbai (India) | Mob: +919821286118 Email: [EMAIL PROTECTED] | Man is made by his belief, as He believes, so He is. | --- Bhagavad Gita |_______Oooo________ oooO( ) ( ) ) / \ ( (_/ \_ ) "Patnaik, Tirthankar " <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 05/10/2007 07:12 PM To <r-help@stat.math.ethz.ch> cc Subject [R] Getting the last day of the month. Hi, Given a date, how do I get the last date of that month? I have data in the form YYYYMM, that I've read as a date using > x$Date <- as.Date(ISOdate(substr(x$YearEnd,1,4),substr(x$YearEnd,5,6),1)) But this gives the first day of the month. To get the last day of the month, I tried > as.Date(as.yearmon(x$Date,frac=0)) But I don't get the last day of the month here. (Tried frac=1 too.) I then add a month to the date, substract one day from the resultant date. But this wouldn't work for December. > x$YearEnd [1] 200203 200303 200403 200503 200603 200603 200312 200503 200603 200203 200303 [12] 200403 200503 200512 200612 200203 200303 200403 200503 200603 > > x$Date <- as.Date(ISOdate(substr(x$YearEnd,1,4), + as.integer(substr(x$YearEnd,5,6))+1, + 1))-1 > x$Date [1] "2002-03-31" "2003-03-31" "2004-03-31" "2005-03-31" "2006-03-31" "2006-03-31" [7] NA "2005-03-31" "2006-03-31" "2002-03-31" "2003-03-31" "2004-03-31" [13] "2005-03-31" NA NA "2002-03-31" "2003-03-31" "2004-03-31" [19] "2005-03-31" "2006-03-31" So I add a year, and set the month to 1 in a quick function. > GetEOM <- function(yyyymm=200406){ year <- as.integer(substr(yyyymm,1,4)) month <- as.integer(substr(yyyymm,5,6)) if (month==12){ date <- as.Date(ISOdate(year+1,1,1))-1 }else{ date <- as.Date(ISOdate(year,month+1,1))-1 } print(date) } x$Date <- as.vector(sapply(x$YearEnd,GetEOM)) str(x$Date) Is there a simpler way to do this please? TIA and best, -Tir Tirthankar Patnaik India Strategy Citigroup Investment Research +91-22-6631 9887 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code. ============================================================================================ DISCLAIMER AND CONFIDENTIALITY CAUTION:\ \ This message and ...{{dropped}} ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.